CYA 3rd day--shows too high

[jmart]

reads cya of 55 on taylor TF-100 kit. With new well water, pool math showed to add 67oz so I added 64oz 3 days ago. Is it apt to go up or down in a weeks time?
anyways, here are the other numbers,

fc--2
cc--0
tc--2
cl--3
ph--7.2
ta--130
cya-55

 

[Richard320]

55 CYA is fine. Unless you were targeting 40, then there is some kind of problem, either with the pool volume or with your testing.

The test itself is pretty subjective, and the readings can change quite a bit just depending on the light. If I hold the view tube naturally, it reads different than if I just hold the very top between thumb and forefinger.

CYA should stay pretty consistent after it's been dissolved and had time to completely mix with the pool water. You'll lose a little bit over time to splashout and backwashing.

 

[jmart]

Thank you for responding.
As suggested, I targeted 40 cya for this pool, so if 55 is fine, that would be great!
But also, I don't fully understand what to do about the 3 chlorine numbers I showed above. I'd appreciate some advice.

 

[Mr Bruce]

Your FC is WAY too low for a CYA of 60 (round up). Pool School - Chlorine / CYA Chart

 

[Richard320]

Thank you for responding.
As suggested, I targeted 40 cya for this pool, so if 55 is fine, that would be great!
But also, I don't fully understand what to do about the 3 chlorine numbers I showed above. I'd appreciate some advice.

If you go to poolmath and down in the last row select your methods and pool material, it will autofill suggested values.

It will give you a range for FC, like 4-9. 4 is the absolute minimum to which you should ever let the FC drop. What you choose as a target depends on how much you lose every day. Every pool is different, depending on sunlight, bather load, how much debris falls in, dogs swimming, whatever. You will quickly learn by daily testing just how much you lose.
So... let's say you target 9. The next day you find you have 6.5 FC left before you dose again. That's above 4, so you can aim a little lower. So you target 8. The next day maybe you're at 6. So you target 7. And maybe you end up at 4.5. That's above 4, but cutting it pretty close. So you might want to target 7.5. In a few weeks you'll know pretty much exactly how much bleach to add every day, and can even guess your test results with amazing accuracy before you start. Just test and dose and pay attention and it will suddenly all make sense.

 

[jmart]

So according to pool math, I targed my fc to be 7 and the recommendation was to add 104oz of bleach. Does that sound correct? and that will take care of the cc and tc numbers right?

 

[Mr Bruce]

I get 93 oz of 8.25% so close enough.

Correct!

 

[jmart]

OK, great. So my plan is to add 104oz of bleach now ( I'll dbl check the math) and then I'll check the numbers daily until I have a better understanding of it. Thanks for the confidence everyone. Jerry

 

[jmart]

So it's been 2 days and the water looks great.
Today's results:
FC--7.5
CC--0
PH--7.5
TA--125
CH--25
CYA-55
So with a PH target of 7.7, pool math suggests adding 22oz borax which I'm about to do.
My plan now is to do the chlorine drop test daily until I get a handle on it and all other tests weekly.
Is this the correct approach?

 

[Mr Bruce]

Hold off on raising pH. There is nothing wrong with 7.5. It may rise on its own.

Do pH every time you do chlorine too. And yes, the other tests can be weekly.

Nice job!

 

[jmart]

OK Mr Bruce, I'll take your advice and continue to monitor as you suggested, thank you,-- Jerry.

 

[doc8404]

Mr. Bruce is surely correct. My pH is hovering at 7.2 and I will let it ride!

 

[jmart]

Great! thanks guys, I'm starting to think that I can do this.

 

[doc8404]

you can, stick around here, I'm new but this is easy!